Improvement in dies for heading screw-blanks



' UNITED STATES PATENT OFFICE.

HAYVARD A. HARVEY, OF NEW YORK, N. Y.

IMPROVEMENT IN DIES FOR HEADING ,SCREW-BLANKS.

Specification `forming part. of Letters Patent No. 44,090, datedSeptember 6, 1864.'

To all whom it may concern: n

Be it known that I, HAYWARD A. HARVEY, ot' the city, county, and Stateof New York, have invented a new and improved die in which screw-blanks,rivets, and other similar articles may be iliade; and I do herebydeclare that the following, taken in connection with the drawings, is afull, clear, and exact description thereof.

In the drawings, Figure lis a side elevation of a heading-machineexhibiting one ot' the forms of my improved die. Fig. 2 is a verticalsection on a larger scale through a die and shear-plate, theheading-punch being shown in elevation; and Fig. 3 is an elevation ofthe cam, showing the groove which'gives motion to the feeding apparatus.

My invention relates to the die only, which may be used in any suitablemachine, and I have represented and described a whole machine merely toexhibit one way ot applying the die to practical use.

In.the drawings, the frame of the machine is shown at a a. In this frameis mounted a shaft, which may be revolved by any suitable machinery.This shaft has mounted upon it a cam, and also an eccentric, which worksin a block that slides in proper ways in a punchstock, to which issecured a punch, b. The revolution of the shaft causes the punch toreciprocate.

A lever is pivoted at its upper end to the frame, and has attached toand projecting from ita pin, which enters the groove in the cam. Thislever is at its lower end connected with an oscillating connecting-rod,which latter is at its other end connected to a vibrating rockshaft, inwhich are mounted a series of dogs. These dogs engage with ratchet-teethon one ot' the feeding-rollers, clearly shown at c. As the main shaftrevolves this feeding-roller will be caused to move with an interruptedrotary motion.

An upper feeding-roller, d, is mounted above the other upon swingingbearings, and is forced toward the lower feeding-roller by a spring. Thewire or rods from which the screw-blanks or rivets are to be made is fedinto the die between these rollers.

A11 opening or aperture is cut through that part of the frame betweenthe feeding-rollers and the punch, and a shear-plate, e, is affixed tothe frame, the aperture through it being a continuation of that throughthe traine. The die ff is mounted on the same part of the frame, and asthe machine shown in the drawings is otl that variety in which the diemoves and forms one of the shear-blades the die is confined in properslides, and is forced to move up and down to shear off lengths of therod by an arm, g, attached to the punch-stock and provided with a slotwhich embraces a pill attached to the die.

In suoli a machine any ofthe ordinary kind of dies might be used. Suchdies are usually of two varieties -solid dies and parting diesand bothclasses are objectionable in use, especially where the shanksof therivets or screwblanks are comparatively long and small in diameter. The.solid dies admit ofthe formation of a good smooth head without tins; butthe shanks are apt to bend while the head is formed, this bending beingtechnically termed crippling.7 The parting dies, 0n the contrary, holdthe wire or rod so firmly round the shank ot' the rivet that nocrippling takes place, but the parting in the dies usually produces aiin on the underside ot' the head.

My invention is intended to obviate the dii'- culties incident to theuse ot' each of these kinds ot' dies; and it consists in making the diein at least two pieces, with the countersink or matrix for the headformed in one part thereof only, while both parts are so formed as togrip the shank of the blank to be formed between them, substantially asdescribed.

In the form in which my invention is exhibited in the drawings that partof the die which contains the counter-sink or matrix for the head of therivet or screw-blank is shown atf and the other part at f. Both piecesslide. in the same ways or guides in order to secure 1 perfect matchingof the parts; and in the drawings the piece f" is shown as attached to aspring, which forces it downward for a certain distance and then holdsit so that the other part of the die, as it is carried down, may moveslightly away from it.

The action of the parts is as follows: The feed-rollers supply themachine with a proper length of wire. The dies then rise and cut thelength of the Wire oft. .Inst before thc axis of the wire comes oppositeto that of the punch the piece f', which has been i'orced upon the. wireby the spring, strikes against the frame and grasps the wire rmlybetween itself and the other part ot' the die. The punch, which has beenadvancing during the upward movement of the dies, now strikes the Wireand heads the blank. Itthen retreats and the dies descend, the headedblank being discharged by the entrance ot' the succeeding piece of Wire.

The closing of the two'parts ofthe die upon the wire prior to theformation ot' the head eft'ectnall y prevents crippling, and the head iswithout ins on the under side, as it is formed in a matriX cut out inthe solid part of the die, there being no joint or fissure in that partof the die which determines the shape of the head.

The formation of the die may be variously modified, so long as that partthereof in which the head is formed is solid, or, in other words, has noparting in it, and so long as the other part of the die has a partingwhereby the parts of the die may be caused to grip the Wire or rod so asto prevent crippling, as described.

The precise mechanical means which may be used for causing the parts ofthe die to close upon the Wire prior to the heading thereof areunimportant, and I intend at times to make the piecef stationary, and tomove the other part of the die to and from it, and the piece f may covera greater or less part of the length of the blank or of its diameter, so

long as it holds the wire `fast at thc time ot" heading'. 'I sometimesintend to cuta slot through a solid die and to make the piece j' like aWedge or key, sliding in the slot in lines either perpendicular orparallel or inclined to the axis ofthe blank so as to grip the blank butin all cases that part of the die in which the head is formed must haveno parting in it, and the other part must be so formedthat it clamps orholds the blank as in a vise prior to and at the instant when the headis formed; and in case the blank should be clamped only for a small partof its length, itis to be understood that such clamping ought to be nearthe under side of the head.

l claim as of my own invention- A die having the counter-sink or matrixfor the head formed in one part only thereof, so as to avoid filming, asdescribed, and having also a capacity to clamp the shank to preventcrippling by a construction, substantially as described, the die as awhole being constructed and capable of operating substantially in themanner hereinbeforc set forth.

In testimony whereof I have hereunto subscribed my name.

El. A. HARVEY.

In presence of'- EDW. E. QUlMBy, Guns. BLIVEN.

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